As someone who hasn't been to any, I'm wondering a couple things:
1) Do you have to order tickets online or can you go to where it's held and buy them there?
2) How old do you have to be allowed in? I doubt they'll give tickets to any toddler with enough money, but I also doubt 16-year-olds must be accompanied by an adult.
I assume these things vary from concert to concert? If anyone could give me any information, I would be very thankful.